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Research Branch 
Technical Bulletin 1997-2E 

Descriptive 

sensory 

analysis: 

The profiling 

approach 



Canada 



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to improve the long-term competitiveness of the Canadian 

agri-food sector through the development and transfer of new 

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Designed by Research Program Service. 

Illustration de la couverture 

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Descriptive 

sensory analysis: 

The profiling 

approach 



L.E JEREMIAH, L.L. GIBSON and 

K.L. BURWASH 

Research Centre 

Lacombe Alberta 

Technical Bulletin 1997-2E 



Research Branch 
Agriculture and Agri-Food Canada 

1997 



Copies of this publication are available from 

Director 

Lacombe Research Centre 

6000 C&E Trail 

Lacombe, Alberta 

T4L 1W1 



© Her Majesty in Right of Canada as Represented by 
Public Works and Government Services Canada 1997 
Cat. No. A54-8/1997-2E 
ISBN 0-662-25-963-7 
Printed 1997 



SUMMARY 

At the point of consumption, palatability or eating satisfaction is the primary determinant of consumer acceptability. 
Palatability is determined by the flavor and texture of the food product. The flavour and texture of a food product 
are determined by their components (character notes) and the arrangement (order of appearance), and intensity of 
these components. Consumers are primarily interested in the overall palatability, texture, and flavour of a food 
product and the extent to which these properties meet their personal expectations for that particular food product. 
However, in research and product development it is often necessary to look beyond overall palatability, texture, and 
flavour and evaluate the individual components of these properties in a similar fashion by which art and music are 
evaluated. This can be accomplished by using descriptive sensory analysis and the profiling approach to food 
texture and flavor. This bulletin provides details regarding the profiling approach, character notes, intensity, order 
of appearance, aftertastes and afterfeelings, and amplitude (overall impression). 



RESUME 

A l'6tape de la consommation, la palatability determine l'acceptation du consommateur pour un produit alimentaire. 
La palatability est deTinie comme e"tant la flaveur et la texture du produit. et celles-ci sont determiners par les 
composantes (notations de tendrete), Parrangement (l'ordre d'apparition) et l'intensite de ces composantes. Le 
consommateur est principalement interesse" par la palatability, la texture et la flaveur g6n£rale d'un produit 
alimentaire et jusqu'a quel point le produit satisfait a son attente. Lors du d^veloppement d'un produit alimentaire, 
plus particulierement au niveau de la recherche, il est souvent utile de voir au dela de la palatabilite, de la texture et 
de la flaveur afin d'6valuer les composantes individuelles de chacune de ces proprtetes, comme on le fait pour 
^valuer les arts ou la musique. Ceci peut etre accomplie, en utilisant une analyse sensorielle descriptive et en 
etablissant des profils pour ^valuer la texture et la flaveur. Ce bulletin, offre une information d£taill6e sur les profils, 
les notation de tendrete, l'intensite, l'ordre d'apparition, la persistance gustative, l'impression r£siduelle et 
l'amplitude (impression g6n6rale). 



Digitized by the Internet Archive 
in 2013 



http://archive.org/details/descriptivesenso19972jere 



Table of Contents 

Background 1 

Character Notes 2 

Aroma 2 

Flavour 2 

Taste 2 

Mouthfeelings 3 

Texture 3 

Hardness 4 

Cohesiveness 4 

Springiness 4 

Viscosity 4 

Adhesiveness 4 

Fracturability 4 

Gumminess 4 

Geometrical Characteristics 5 

Intensity 5 

Order of Appearance 6 

Aftertastes and Afterfeelings 7 

Amplitude 7 

The Profiling Approach 8 

Background 8 

The Approach 8 

The Panel 9 

The Results 10 



B 



ackground 



Sensory evaluation is the qualitative 
assessment of a material based upon 
perceptions arising from sensations detected by the 
eyes, ears, nose, tactile nerves, and/or taste buds. 
Such perceptions are formulated by the brain which 
analyzes the interaction of sensations resulting from 
the stimulation of various receptors (i.e. the eyes, 
ears, nose, tactile nerves, and taste buds). 

The use of humans in sensory evaluation of aroma, 
flavour, and texture is necessary because no 
mechanical device can measure the perception 
formulated by the human mouth, nose, and brain. 

However, when humans are utilized for sensory 
evaluation it is necessary to rigidly control all testing 
methods and conditions to eliminate potential biases 
arising from psychological factors. 

Panels utilized in sensory evaluation can consist of 
highly trained experts, experienced laboratory 
personnel, or untrained consumers. In general, highly 
trained and/or experienced laboratory panels are 
utilized to describe factors contributing to the quality 
of a product, while consumer panels are employed to 
estimate consumer response to a product. 

There are three basic questions to be answered 
through sensory evaluation: 

1) Is there a detectable difference between food 
samples? 

Answered by difference tests utilizing 
psychophysics and a laboratory panel 

2) How well do people like a food product? 

Answered by consumer preference tests utilizing 
psychometrics 

3) What are the palatability attributes of a food 
product? 

Answered by profile panel tests utilizing 
phenomenological description 

Descriptive analysis is considered to be the most 
sophisticated sensory evaluation method presently in 
use, and is the only method that deals with the total 
perception of a product. The three most popular 
methods of descriptive analysis are flavour profiling, 



texture profiling, and quantitative descriptive 
analysis. 

Descriptive analysis requires at least 3 evaluation 
processes including discrimination, description, and 
quantification of individual characteristics. 

Discrimination is the detection of those 

characteristics that contribute to the overall 
flavour, aroma, and texture. 

Description is the process of describing each of these 
character notes using meaningful common 
language and terminology. Discrimination and 
description together provide a definition of the 
qualitative aspects of a product or those notes 
that combine to make a product what it is. 

Quantification is the process of determining the 
intensity and order of appearance of each 
character note. 

Therefore, descriptive analysis is a complex 
cognitive process requiring more mental acuity than 
sharp taste and olfactory senses, since sensory stimuli 
must not only be detected, but must also be 
described. 

By definition descriptive analysis seeks to describe 
and analyze all perceived characteristics of aroma, 
flavour, and texture. Therefore, it is essential that 
such sensory data be as objective and as free from 
opinion as possible. This necessitates the use of 
standard terminology, standard reference samples, 
and standard evaluation procedures to aid in 
eliminating subjective judgments from panel data. 

Appropriate language is developed through careful 
training and practice, during which the panel 
develops a common vocabulary or a flavour, aroma, 
and texture mental library which catalogues various 
sensory stimuli with appropriate names. 

Flavour and texture profiling are two of the most 
popular methods of descriptive analysis. 

Flavour profiling is the sensory analysis of the aroma 
and flavour complex of a food product in terms 
of its aromatics, basic tastes, and mouthfeeling 
sensations, the degree of each present, and the 
order in which they appear from the initial 
sensation to residual sensations remaining after 
the sample has been swallowed. 

Texture profiling is the sensory analysis of the texture 
complex of a food product in terms of its 
mechanical, geometrical, and fat and moisture 
characteristics, the degree of each present, and 
the order in which they appear from the initial 



mouthfeeling to residual sensations remaining 
after swallowing. 

Therefore, the dimensions of the profile method 
include: 

1) character notes or perceptible aroma, flavour, 
and texture factors 

2) degree of intensity of each factor 

3) order in which these factors are perceived 

4) aftertastes or afterfeelings 

5) amplitude or overall impression 



C 



haracter Notes 



are the detectable parameters that define 
the flavour, aroma, and texture of a 
product, and include: 

1) components of aroma composed of olfactory 
sensations perceived by the olfactory nerve and 
nasal feelings perceived by the tactile nerves in 
the nose 

2) components of flavour by mouth composed of 
olfactory sensations perceived by the olfactory 
nerve, taste sensations perceived by the tastebuds 
on the tongue, mouthfeel sensations perceived 
by the tactile nerves in the mouth and nose, and 
afterfeel/aftertaste sensations or taste, olfactory, 
and/or feeling sensations remaining after 
swallowing 

3) components of texture composed of mechanical 
sensations perceived by the kinesthetic sense as 
reactions of the product to stress, geometrical 
sensations perceived by the tactile nerves in the 
mouth related to size, shape and arrangement of 
particles, fat and moisture sensations perceived 
by the tactile nerves in the mouth related to the 
content and reaction of fat and moisture within 
the product, and afterfeel sensations perceived 
after swallowing (geometrical and/or fat and 
moisture sensations). 

There are only two types of senses: chemical senses 
(taste, smell, and feeling), and physical senses (sight 
and sound). 

Aroma is the odor sensation of a substance perceived 
by olfactory and tactile nerves in the nasal cavity 
either by direct sniffing through the nostrils or 
passively through the passage at the back of the 



mouth, including both odor and feeling factors. 
Olfaction is the sense of smell or the perception of 
odors by nerve cells in the nasal area. Odors are 
perceived by the olfactory cells located at the upper 
region of the nasal cavity, but only a small portion of 
any substance reaches the olfactory region. 
Obstruction of air passages in the nasal cavity can 
greatly reduce olfactory perception. Since the top of 
the throat and the nasal cavity are joined odors can be 
perceived through the pharynx as well as through the 
nose. Anosmia is odor blindness. 

Components of aroma are either olfactory sensations 
perceived by the olfactory nerve (fruity, floral, 
rancid, sulfury, etc.) or nasal feelings perceived by 
the tactile nerves in the nose (cool, pungent, etc.). 

Aroma is normally evaluated before flavour since 
odor notes may be overpowered or masked when the 
food is eaten. 

Flavour by mouth consists of taste factors, feeling 
factors, aromatic factors, and aftertastes or 
afterfeelings. Identity of a food flavour depends 
upon the concentration of specific chemicals released 
during eating and the specific sensitivity of the 
consumer. Components of flavour by mouth are 
either: 

1 ) taste sensations perceived by the taste buds on 
the tongue (sweet, salty, sour, bitter) 

2) mouthfeel sensations perceived by the tactile 
nerves in the mouth (cool, metallic, hot, cold, 
astringent, etc.) 

3) aromatic sensations perceived by the olfactory 
nerve (vanilla, fruity, floral, etc.) 

4) aftertaste sensations (aromatic, taste, and/or 
feeling factors) perceived after swallowing that 
resemble those prior to swallowing. 

Flavour results from chemical stimulation of the taste 
buds in the mouth, the olfactory nerve and organs in 
the nose, and the nerves and organs of feeling in the 
mouth throat, and nose. Only a portion of the 
chemicals in a given food will be sensed. For 
example, brewed coffee flavour is readily recognized 
but only bitter and sour can be tasted, only 
astringency felt and only the "bouquet" aroma 
detected. 

Taste is the sense by which certain properties are 
perceived through taste buds on the surface of the 
tongue. There are only four tastes; sweet, salty, sour, 



and bitter. These are often referred to as basic or 
primary factors, since physiologists have shown that 
only these sensations will stimulate the taste buds. 
Different tastes are sensed on different surfaces of the 
tongue. Sensitivity is mostly on the edges of the 
tongue and not in the middle. 



Bitter 



Sour 



Salt 




Sour 



Salt 



Sweet 



Papillae are the bumps on the tongue and are of four 
types: foliate, circumvallate, fungiform, and filiform 
(no taste buds). Some papillae are known to respond 
more to one taste stimulus than to another. However, 
the manner in which taste buds react to stimuli is not 
definitely known. 

Factors influencing taste perception are disease 
producing aguesia (taste blindness), temperature, 
medium used (solid or liquid), viscosity, number of 
taste sensations present, and chemical configuration 
(since different isomers may differ in the amount of 
response they elicit). 

The effect of temperature varies for different 
substances. Different flavour factors are sensed 
separately and at different times, although the total 
time span may be only microseconds. Each 
detectable flavour has its own time-intensity curve. 
However, most flavour sensations build up rapidly to 
a peak and then dissipate rapidly. 

Mouthfeelings are sensations perceived by the nerves 
in the skin of the mouth cavity resulting from thermal 
and chemical reactions. Thermal reactions result in 
perceptions of hot and cold. 



Example 1= ice (thermal cold) 

Example 2= hot water (thermal hot). 

Chemical feeling factors are less well defined 
physiologically. 

Example 3= cayenne pepper (chemical hot or bite) 

Example 4= peppermint candy (chemical cool) 

Example 5= ferrous sulfate (metallic) 

Example 6= spearmint gum (green) 

Example 7= horseradish (chemical burn) 

Example 8= club soda (prickly) 

Therefore, flavour is all of the sensations of taste, 
smell, and feeling when a food is being consumed. 

Texture is the sensory manifestation of the structure 
or inner makeup of foods. The components of 
texture are: 

1) mechanical sensations perceived by the 
kinesthetic sense as a reaction of the product to 
stress; such as hardness, cohesiveness, 
brittleness, chewiness, gumminess, viscosity, 
springiness, and adhesiveness 

2) geometrical sensations related to the size, shape, 
and arrangement of particles perceived by the 
tactile nerves in the mouth; such as, powdery, 
chalky, grainy, gritty, coarse, lumpy, beady, 
flaky, fibrous, pulpy, cellular, aerated, puffy, 
crystalline, stringy, smooth, etc. 

3) fat and moisture sensations related to the content 
and reaction of fat and moisture perceived by the 
tactile nerves in the mouth; such as, moistness, 
oiliness, moisture release, moisture absorption, 
and saliva thickening 

4) afterfeel sensations such as, geometrical or fat 
and moisture sensations remaining as residues 
after swallowing. 

Order of appearance in texture evaluation is fixed. 
Surface characteristics are evaluated first, then 
characteristics perceived on partial compression and 
the first bite are evaluated, such as elasticity, 
hardness, compressibility, cohesiveness, etc. 
Characteristics perceived during mastication are then 
evaluated such as, chewiness, moisture absorption 
and release. Afterfeel sensations are evaluated after 
swallowing. 

The texture of samples rarely differs due to the order 
of appearance of character notes. Occasionally one 



sample will disappear more quickly then another, but 
this will be accounted for by evaluations of 
cohesiveness, chewiness, and rate of disintegration, 
etc. 

Primary mechanical characteristics consist of 
hardness, cohesiveness, viscosity, springiness, and 
adhesiveness. All primary mechanical characteristics 
except adhesiveness are related to forces of attraction 
acting between particles of food and opposing 
disintegration. Adhesiveness is related to surface 
properties. 

Hardness is the force required to compress a 
substance between the molar teeth (in the case of 
solids) or between the tongue and palate (in the case 
of semi-solids). Hardness is evaluated by placing a 
sample between the molar teeth and biting down 
evenly, evaluating the force required to compress the 
food. 



Intensity of hardness: 
Soft - Firm - 



Hard 



Peanuts - Carrots - Almonds - Rock 
candy 

Cohesiveness is the degree to which a substance is 
compressed between the teeth before it breaks. 
Cohesiveness is evaluated by placing a sample 
between the molar teeth, compressing it, and 
evaluating the amount of deformation before rupture. 

Intensity of cohesiveness : 

Easy to disintegrate - Hard to disintegrate 

Taco chips - Carrots - Bread - Meat 

Springiness is the degree to which a product returns 
to its original shape once it has been compressed 
between the teeth. Springiness is evaluated by 
placing the sample between the molar teeth, if a 
solid, or between the tongue and palate, if a semi- 
solid, compressing it partially and then removing the 
force, evaluating the degree of quickness of recovery 

Intensity of springiness: 

Plastic (easily molded) - Elastic 

Taffy - Carrots - Bread - Meat 

Viscosity is the force required to draw a liquid from a 
spoon over the tongue. Viscosity is evaluated by 
placing a spoonful of sample directly in front of the 
mouth and drawing the liquid from the spoon over 
the tongue by slurping, evaluating the force required 
to draw the liquid over the tongue at a steady rate 



Intensity of viscosity: 

Thin - Thick - Viscous 

Water - Orange juice - Karo syrup - Honey 

Adhesiveness is the force required to remove the 
material that adheres to the moth (generally the 
palate) during the normal eating process. 
Adhesiveness is evaluated by placing the sample on 
the tongue, pressing it against the palate, and 
evaluating the force required to remove it with the 
tongue. 

Intensity of adhesiveness: 

Sticky - Tacky - Gooey 

Carrots - Rock candy - Bread - Peanut butter 

Secondary mechanical characteristics consist of 
fracturability, chewiness, and gumminess and 
contribute to cohesiveness. 

Fracturability is the force with which a sample 
crumbles, cracks, or shatters. Fracturability is 
evaluated by placing the sample between the molar 
teeth and biting down evenly until the food crumbles, 
cracks, or shatters, evaluating the force with which 
the food moves away from the teeth. 



Intensity of fracturability (Brittleness): 



Crumbly 



Crunchy 



Brittle 



Meat - Peanuts - Granola bars - Taco chips 

Chewiness is the length of time in seconds required 
to masticate a sample at a constant rate of force 
application to reduce it to a consistency suitable for 
swallowing. Chewiness is evaluated by placing a 
sample in the mouth and masticating it at one chew 
per second at a force equal to that required to 
penetrate a gum drop in 54 second, evaluating the 
number of chews required to reduce the sample to a 
state ready for swallowing. 

Intensity of chewiness: 

Tender - Chewy - Tough 

Cheese - Meat - Licorice - Taffy 

Gumminess is the denseness that persists throughout 
mastication or the energy required to disintegrate a 
semi-solid food to a state ready for swallowing. 
Gumminess is evaluated by placing the sample in the 
mouth and manipulating it with the tongue against 
the palate, evaluating the amount of manipulation 
necessary before the food disintegrates. 



Intensity of gumminess: 

Short - Mealy - Pasty - Gummy 

Butter - Cream cheese - Cottage cheese - Peanut butter 

Geometrical characteristics are related to the size 
and shape of particles (gritty, grainy, etc.) perceived 
as discrete particles relatively harder than the 
surrounding medium or carrier, or are related to the 
shape and orientation of the particles (fibrous, flaky, 
etc.) in highly organized structure of different 
geometrical arrangements within the product. 

Particle size and shape: 

Chalky - Gritty - Grainy - Coarse 

Particle shape and orientation: 

Fibrous - Cellular - Crystalline 

Powdery = dusty, friable, or in the form of power 

Example = confectioner's sugar 
Chalky = having a chalk-like texture 

Example = raw potato, tooth powder 
Grainy = granular, consisting of grains 

Example = cream of wheat, farina, wheatlettes 
Gritty = sandy, containing grit 

Example = sand, pears 
Coarse = consisting of rather large particles 

Example ■ cooked oatmeal 
Lumpy = covered with or full of lumps 

Example = cottage cheese 
Beady = full of or covered with drops or bubbles 

Example = tapioca pudding 
Flaky = containing or made up of flakes 

Example = boiled haddock 
Fibrous = containing or composed of fibers 

Example = breast of chicken 
Pulpy = containing or composed of pulp 

Example = raw orange sections 
Cellular = consisting of or containing discrete cells 

Example = raw apple, white cake 
Aerated = containing pockets of air 

Example = chiffon pie filling, marshmallows 



Puffy = puffed, swollen, inflated 

Example = puffed rice 
Crystalline = consisting of or composed of crystals 

Example = granulated sugar 
Stringy = consisting of strings or tough fibers 

Example = celery 

Other textural characteristics are related to the 
perception of moisture and fat. Moisture is evaluated 
not only for the amount present, but also for the rate 
and manner of absorption or release. Fat is evaluated 
not only for the amount present, but also for its type 
and rate of melting. 

Moisture content: Dry - Moist - Wet - Watery 

Fat type: Oiliness 

Greasiness 



I 



ntensity 



■Intensity is the degree to which each character 
note is present in the sample being evaluated 
and represents one of the quantitative aspects of the 
product. Intensities can be expressed or quantitated 
using several scaling procedures including: 1) 
category scales, 2) linear scales, and 3) magnitude 
estimation. 

A category scale is a set of equally spaced categories 
anchored with numbers and adjectives into which a 
series of stimuli must be fit. A linear scale is a 
straight line of fixed length which may or may not 
have anchor points on which the panelist marks the 
distance representative of the intensity in question. 
Magnitude estimation is a ratio scale. 

With magnitude estimation the intensity of a given 
stimulus is assigned a positive number and the 
intensities of other stimuli in the same or other 
samples are assigned numbers in proportion to the 
first rating given. The first rating may be of the 
panelist's choice or may be fixed by the panel leader 
using reference samples of fixed intensity. Thus 
magnitude estimation can be used either with or 
without a fixed modulus. However, when the 
modulus is not fixed the data must be normalized to 
facilitate comparisons among panel members and 
pooling of panel data. 



When it is either desirable or necessary to compare or 
pool data over panel sessions or to compare the 
intensity of one characteristic to another, the panel 
must be trained to rate intensities across 
characteristics. For example, one lemonade may be 
rated 10 for sweetness, while another lemonade may 
be rated 15 for sweetness to reflect a sweetness 1.5 
times as strong. In the same context, chocolate 
pudding and apple pie of equal sweetness would 
receive sweetness ratings of equivalent intensity. 
Also lemonade with a sweetness and a sourness of 
equal intensity would receive equivalent ratings for 
both sweet and sour. 

Two products may have identical qualitative traits or 
components of aroma, flavour by mouth, and texture, 
or the same description or definition, but may differ 
due to the intensity of certain components. 

Threshold is the point on a stimulus scale at which a 
transition occurs in a series of judgments. Absolute 
or detection threshold (AL) is the level of stimulus at 
which a transition occurs from a lack of sensation to 
sensation. Recognition threshold (RL) or 
identification threshold is the minimum level of 
stimulus at which a substance can be correctly 
identified. Difference threshold or just noticeable 
difference (DL) is the least amount of change in 
stimulus which produces a change in sensation. 
Terminal threshold (TL) is the amount of stimulus 
above which increases in intensity can not be 
detected. There are about 25 just noticeable 
differences in tastes and odors from recognition 
threshold to terminal threshold. Above this point 
pain often occurs. 



indicating that the lemon drink was twice as sweet as 
the lemonade. 



AL 



RL 



DL 



DL TL 



A B C D 

People cannot measure with precision taste intensities 
beyond the recognition threshold unless standards are 
provided. 

Threshold levels differ among individuals. Two 
individuals with recognition thresholds for sucrose of 
0.34 and 0.40% may report a 10% sucrose solution to 
be moderately sweet. However, a moderate sweet 
rating (10) should be the same in lemonade as it is in 
pudding. Likewise, sweetness, sourness, and vanilla 
notes perceived to be equal in intensity should 
receive the same intensity ratings. For example, if a 
panelist assigns a rating of 10 to the sweetness of a 
fresh lemonade, he might assign a rating of 20 to the 
sweetness of a carbonated lemon drink, thus 



o 



rder of Appearance 



The order in which different 
characteristics are perceived can be defined. In some 
cases the order of appearance of the character notes 
may constitute one of the most important factors 
contributing to differences in overall impression. 
This is particularly true in the case of flavour since 
the order of appearance of most texture character 
notes is predetermined by the evaluation process. 
Therefore, texture rarely differs due to the order of 
appearance of character notes. Occasionally, one 
sample will disintegrate more rapidly than another, 
but this difference will usually be accounted for in 
ratings of chewiness, rate of breakdown, etc. 

If the exact order of appearance flavour character 
notes cannot be determined, character notes can be 
classified as appearing early, middle, and late. 

The texture profile procedure follows. 

During the initial phase or before biting into the 
sample or manipulating it in the mouth, geometrical 
and fat and moisture characteristics associated with 
the surface are perceived. These include surface 
moisture, surface roughness (smoothness), the 
presence of surface particles having a particular 
geometrical characteristic, etc. 

During partial compression with the molar teeth or 
the tongue and palate, elasticity or springiness are 
evaluated. 

During the first bite with the molar teeth mechanical 
and geometrical characteristics are perceived, as well 
as moisture and/or fat release and absorption. 

During mastication (chewing) all textural properties 
are perceived. Particular attention should be given to 
moisture and fat absorption and release and to the 
appearance of or changes in different geometrical 
characteristics. 

During the residual phase all geometrical and fat and 
moisture characteristics remaining after the sample 
has been swallowed are perceived. Particular 
attention should be given to mouth dryness, oiliness, 
ease of swallowing, etc. 



A 



ftertastes and Afterfeelings 



When a bite of food is eaten or a sip of 
beverage is drunk the entire sensation of flavour and 
texture usually lasts only a few seconds. However, 
some foods and beverages even after being 
swallowed leave a flavour or texture residue termed 
aftertastes or afterfeelings. 

Aftertaste is not a miniature of the whole flavour in 
all cases, but may well be just delayed effects such as 
astringency, dryness, or long-lasting factors such as 
bitterness. 



A 



mplitude 



Attempts are often made to measure the 
overall or total impression of flavour and texture 
since they are multivariate systems. However, the 
types of ratings of overall impression that can be 
obtained is dependent upon the extent of training the 
panel has received with regard to the evaluation and 
integration of factors constituting the total 
perception. 



A highly trained panel can rate the overall intensity 
of flavour and texture, with some difficulty, by 
considering all of the character notes, and their 
intensities. The difficulty arises since the intensities 
of the individual character notes are not additive. 
Individual sensations interact to produce patterns or 
configurations which are not properties of the 
individual sensations themselves, but rather a 
function of the way they are arranged or organized 
within the interaction. Therefore, the overall flavour 
intensity cannot be considered to be a composite of 
the individual sensations. 



The amplitude of both flavour and texture is often 
rated when a profiling approach is utilized to reflect 
balance blendedness and appropriateness of all of the 
character notes present and their intensities and order 
of appearance. Appropriateness of the character notes 
is determined by what character notes are expected to 
be present in a given product. For example, orange 
juice is expected to have fresh orange aroma, 
sweetness, sourness, etc. Likewise saltiness is 
expected in potato chips but not in strawberry jam. 
Therefore, if saltiness is detected in strawberry jam, 



particularly at high intensity, it would detract from 
the flavour amplitude. Balance and blendedness 
refers to the relative balance of the character notes 
present, in relation to what is expected for a given 
product type. For example, if a given character note , 
even though appropriate, is too weak or too intense it 
will detract from the amplitude. Hence, if a 
lemonade is too sour or has too weak of lemon 
aromatic this will detract from the flavour amplitude. 
Therefore, in a sense, amplitude ratings reflect an 
evaluation of the overall product quality. 



However, the problem in analyzing amplitude is not 
how to measure it, but rather how such data can be 
interpreted and utilized. For example, if a product is 
given high flavour and/or texture amplitude ratings 
by a group of sensory experts, does this imply 
consumer acceptance? The answer is no, since 
consumers do not always prefer products that are the 
most fresh, most natural, most well blended, and/or 
most free from offnotes. 



A trained panel can also be asked to rate the overall 
difference between a given sample or product and a 
control, reference, or standard sample or product 
provided the panel has an in-depth understanding of 
the total frame of reference in which the samples are 
being evaluated. Hedonic rating are only meaningful 
when they are provided by an untrained consumer 
panel or a carefully selected semitrained laboratory 
panel. Panels intensively trained to objectively 
analyze the components of aroma, flavour, and/or 
texture should never be asked to provide hedonic 
ratings. 



Amplitude constitutes the overall impression of the 
product including the appropriateness of the various 
character notes and their intensities during all phases 
of evaluation. Amplitude in a sense is an evaluation 
of the overall quality of a product, but amplitude 
ratings must not reflect personal or consumer 
preferences, since consumers do not always prefer 
products that are the freshest, most natural, or most 
well blended. 



Determination of amplitude or overall flavour 
impression depends upon rating of the balance, the 
blendedness and appropriateness of the 
characteristics and their intensities. It requires a firm 
knowledge of the place each product fits into the total 



frame of reference. For example, does an orange 
juice have fresh orange character, sweetness, 
sourness, etc.? Are these characteristics properly 
balanced and is the product well put together in 
relation to other orange juices? 



Flavour amplitude or overall flavour intensity is 
based on the combination of aromatics, basic tastes, 
mouthfeelings, and aftertastes. 

In general, product flavours with two or more high 
intensity characteristics will generally be rated higher 
or more intense in amplitude than those with several 
low intensity characteristics. 



The Profiling Approach 



B 



ackground 



Flavour and texture perception is not a 
composite of individual sensations since individual 
sensations interact to produce patterns or 
configurations which are not properties of the 
individual sensations themselves, but rather a 
function of the way they are arranged or organized. 
For example, when viewing a painting we usually do 
not notice the individual brushstrokes, but the 
integrated whole. Likewise, when listening to music, 
we are not so aware of the individual notes as we are 
the melody. When we eat a steak we are not as 
aware of the hardness or compressibility of the 
muscle fibers, or the cohesiveness or coarseness of 
the meat as we are the tenderness. We can look 
beyond the initial perception and analyze the 
individual elements (i.e. brushstrokes, notes, 
hardness, etc.) and learn something about the 
organization and arrangement of the whole. 

The palatability of food products can be analyzed and 
evaluated in much the same manner in which art and 
music are analyzed and evaluated. For example, the 
overall impression created by a painting is evaluated 
as well as each individual brushstroke, and the 
melody of music in evaluated as well as each 
individual note. Likewise with profiling the overall 
impression (amplitude) of flavour and texture is 
evaluated as well as all individual character notes, 
their intensities, and their order of appearance. 
Therefore, the profiling approach looks beyond the 
initial perception and analyzes individual elements so 



that the organization and arrangement of the whole 
can be understood. The flavour profile 
accommodates both the overall impression created by 
flavour and aroma and the individual elements that 
contribute to that impression. The texture profile 
accommodates both the overall impression created by 
texture and the individual elements that contribute to 
that impression. 

Thus, since analysis and synthesis are both inherent 
to the perception process, they are both incorporated 
into the flavour and texture profile. The flavour and 
texture profile can be visualized as an open hand with 
the palm being the body and the extended fingers 
representing the individual flavour and odor notes 
that emerge. When one or more of these notes is 
either suppressed or non-existent the profile has 
changed. The composite (whole hand) represents the 
whole flavour or the amplitude. For example, the 
flavour profile of brewed coffee contains the body 
(palm of the hand) represented by unidentifiable 
chemicals which make coffee - coffee without 
creating a flavour impression; and the individual 
notes (fingers) represented by the sour, bitter, 
astringency, and "bouquet" notes. 



T 



he Approach 



The trained profile panel first develops 
appropriate terminology and definitions and for 
texture decides on the order in which characteristics 
are to be evaluated. 

With both flavour and texture profiling a frame of 
reference is developed by the panel itself for each 
product type to be evaluated. The panel then 
discusses the appropriateness of the terminology to 
provide all of the panelists with equal understanding 
of the definition of descriptive terms for the 
qualitative notes and the methodology to be utilized 
for evaluating samples and quantifying intensities 
and order of appearance, and to remove duplication 
and extraneous evaluations from the profile. Once 
the panel has developed the profiling procedures and 
adequately defined their common terminology, 
evaluations of a product can begin. 

To develop appropriate terminology, panelists should 
individually evaluate several samples representative 
of the full range of flavours and textures for a 
particular product type and list all of the terms that 
apply to one or all samples. These terms are then 
discussed and a mutually acceptable list of terms and 



definitions are developed, considering the 
completeness of the list, whether some terms have 
the same meaning and can be combined or deleted, 
and the degree of consensus on each term and 
definition. 

Panelists independently evaluate one sample at a time 
and record all character notes perceived, their order 
of appearance, and their intensities and assign a 
rating to amplitude. After 2 or 3 samples have been 
evaluated independently, the panel assembles as a 
group to discuss their evaluations and to develop a 
consensus profile for each sample. Therefore, 
flavour and texture panels function as teams, even 
though samples are evaluated independently and all 
panelists are professionals, since group perception is 
generally more comprehensive than individual 
perception. 



T 



he Panel 



Reliability and reproducibility of flavour 
and texture profile data is dependent upon the skill of 
the practitioners and the use of objective reference 
standards to eliminate discrepancies. Profiles are 
developed and utilized through experience which 
employs perceptual judgments of both the elements 
and structure of flavour, aroma, and texture by 



carefully selected and intensively trained 
practitioners working as a team to reach a composite 
judgment. Therefore, profiling requires professional 
skills and experience and generally relies on results 
rather than statistics to confirm previous findings. 

The panelists' objective is to become proficient 
enough to be able to write down accurate word 
descriptions of texture, flavour, and aroma, and the 
overall impression or amplitude after 3 sniffs and/or 
3 bites and to be able to answer the following 
questions: 

1) Was the amplitude low, medium, or high? 

2) What were the discernible factors? 

3) How strong was each of these factors? 

4) Which came first, second, third, etc.? 

5) What were the aftertastes and/or 
afterfeelings? 

Such proficiency is gained through both broad and 
intensive training lasting up to one year. Such 
proficiency and training enables the formation of a 
complete flavour/texture profile with texture, aroma, 
and flavour by mouth described and specified as 
accurately as possible, including amplitude or overall 
impression, and description of detectable factors, 
their intensities, and order of appearance. 



The Components 

The components of both the flavour and texture profile are depicted and compared in the following table. 



Components 



Flavour 



Texture 



Character notes 



Intensity 

Order of Appearance 



Olfactory sensations 
Taste sensations 
Nasal sensations 
Mouthfeeling sensations 
Degree of each note present 
Quite unpredictable and 
variable 



Aftertaste/Afterfeel ing 
Amplitude 



Mechanical characteristics 
Geometrical characteristics 
Fat and moisture characteristics 

Degree of each note present 
Follows a definite sequence, 
including the following phases: 

Initial 

Partial compression 

First bite 

Masticutory 

Residual 
Sensations perceived after swallowing Sensations perceived after swallowing 

Overall impression (balance blendedness and appropriateness of individual character notes) 



T 



he Results 



The validity and accuracy of panel 
performance is related to: 

1) reliability of the panel as a whole to 
duplicate findings from one evaluation to 
another 

2) the ability of individual panel members to 
duplicate their findings from one evaluation 
to another 

3) the ability of panel members to agree with 
one another 

Complete profiles consist of descriptions of the 
individual characteristics or character notes, their 
intensities, their order of appearance, and a rating of 
amplitude. Such profiles of food products can be 
compared with profiles for other products or products 
that have been processed or treated differently. 

However, since flavour and texture perception is not 
a composite of individual sensations, but rather a 
function of the patterns and configurations produced 
by the interaction of individual sensations, the 
relativity of the individual sensations and their 
properties (intensities and order of appearance) to 
one another and the types of interactions they 
produce are the most important components of 
flavour and texture perception reflected in complete 
profiles. Therefore, it is essential that complete 
profiles be presented and compared, since 
suppression or deletion of one or more of the 
detectable notes or their properties alters the profile 
and may result in misrepresentation of the data. 
Complete flavour and texture profiles can be 
presented in tabular or graphic form and can be 
analyzed statistically. However, most industrial 
firms utilizing the profile approach prefer not to 
submit their data to statistical analysis. 



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